The Bethesda Softworks Forums have a thread on a new utility for The Elder Scrolls V: Skyrim claiming to offer framerate improvements of up to 40% on CPU-constrained systems (thanks Acleacius). Here's the skinny:

This patch will improve your frame rate by up to 40% in all CPU-dependent situations, i.e. especially in cities. It works mostly by rewriting some x87 FPU code and inlining a whole ton of useless getter functions along the critical paths because the developers at Bethesda, for some reason, compiled the game without using any of the optimization flags for release builds.

There has been some confusion about the original dll file and the current one for Script dragon. Script Dragon's dinput8.dll is 592kb The non working TESV Accelerator dinput.dll is 74kb

The thing that scares me about this is I install it, something goes wrong 5 hours later and I've lost my 100 hour game. For basic mods I'm confident this is fine but something deeper like this? I don't fancy it, not yet.

Back up your saves. They're in Documents/MyGames/Skyrim. It's Copy and Paste from there.

Not always that simple. Sometimes a flag gets flipped that you don't see the effects of until other conditions are met that make the crash occur.